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Biomedical subjects

Osamu Matsui

Publications and source records attributed to Osamu Matsui.

At least 55 records · Page 3Linked to original sources
PubMed2003

Clinical application of a curved nitinol stent-graft for thoracic aortic aneurysms.

PURPOSE: To evaluate the clinical efficacy of a curved nitinol stent-graft for repair of thoracic aortic aneurysms. METHODS: The Matsui-Kitamura stent-graft (MKSG), composed of a self-expanding nitinol stent and polyester fabric, was shaped to match the aortic curvature of 11 patients (6 men; mean age 72.6 years, range 33-90) with 6 true and 5 false aneurysms of the distal arch or proximal descending aorta. The delivery system was an 18 or 20-F J-shaped sheath combined with a preloader-type introducer. The original mean proximal neck length was 16.4 mm, but 4 patients received an axilloaxillary bypass to lengthen the neck. Although the mean corrected proximal neck length was 21.9 mm (overall), 5 cases still had proximal necks <15 mm long. RESULTS: All curved MKSGs were successfully deployed in the correct position and fitted to the curvature of the aortic arch, achieving complete aneurysm exclusion in 8 (73%) cases. The other 3 repairs displayed early endoleaks; 1 received an additional MKSG, but the other 2 are being observed. Thirty-day mortality was 0%. One patient developed transient renal failure requiring hemodialysis; no neurological complications were observed. CONCLUSIONS: Endovascular repair of thoracic aortic aneurysms using curved MKSGs appears to be feasible and clinically effective. A tighter fit of the device to the curvature of the aortic arch may exclude distal arch aneurysms despite a short proximal neck.

Adult↗
PubMed2003

Stent-graft repair of a mycotic left subclavian artery pseudoaneurysm.

PURPOSE: To report successful stent-graft treatment of a mycotic pseudoaneurysm of the left subclavian artery in an immunosuppressed patient. CASE REPORT: A 17-year-old immunosuppressed woman undergoing treatment for recurrent leukemia developed persistent fever and 2 episodes of hemoptysis. A contrast-enhanced computed tomographic (CT) scan demonstrated a saccular aneurysm of the left subclavian artery, which was considered to be a mycotic aneurysm caused by erosive fungal infection from the lung. The pseudoaneurysm was treated with a homemade stent-graft consisting of a nitinol stent and a polyester fabric. A type II endoleak present at the end of the procedure appeared to have sealed spontaneously on the CT scan at 3 days. No neurological deficit or ischemic symptoms of the left arm were noted during the follow-up, which lasted until the patient died 11 months later after rejecting a second bone marrow transplant. CONCLUSIONS: Endovascular repair may be an alternative to open surgery for the management of mycotic aneurysms of the subclavian artery.

Adolescent↗
PubMed2003

Mediastinal bronchial artery aneurysm treated with a stent-graft.

PURPOSE: To report a rare case of mediastinal bronchial artery aneurysm successfully treated with an endovascular stent-graft. CASE REPORT: A 79-year-old man with a history of tuberculosis was admitted to our hospital complaining of worsening hoarseness. Examination revealed a large mediastinal bronchial artery aneurysm located near the origin of the artery. Since neither surgical intervention nor transcatheter embolization was feasible, an endovascular stent-graft repair was performed using a newly developed stent-graft constructed from a nitinol stent and a thin membrane of polyester. Postprocedural angiography showed satisfactory exclusion of the aneurysm. The patient made an uneventful recovery. The 18-month computed tomographic scan documented continued exclusion of the aneurysm, with no evidence of endoleak, graft thrombosis, or migration. CONCLUSIONS: When conventional procedures are too complicated for bronchial artery aneurysms, endovascular stent-graft repair can be a useful approach.

Aged↗
PubMed2003

Dynamic CT of acute cholangitis: early inhomogeneous enhancement of the liver.

OBJECTIVE: Our objective was to describe the dynamic CT findings of acute cholangitis, especially early inhomogeneous enhancement of hepatic parenchyma. MATERIALS AND METHODS: Inhomogeneous enhancement of hepatic parenchyma was retrospectively evaluated on dynamic CT in 406 consecutive patients without irregular fatty liver or multiple hepatic tumors. Dynamic CT scans were obtained 30 sec (early phase) and 90 sec (late phase) after starting the contrast material injection. Thirteen patients were diagnosed as having acute cholangitis (cholangitis group), and the remaining 393 patients were classified as the control group. The frequency of inhomogeneous enhancement was compared between these two groups. In nine of the 13 patients in the cholangitis group, we also evaluated changes in inhomogeneous enhancement on follow-up dynamic CT scans obtained after the patients had undergone treatment for acute cholangitis. RESULTS: In the cholangitis group, 11 (85%) of 13 patients showed nodular, patchy, wedge-shaped, or geographic inhomogeneous enhancement throughout the liver in the early phase on dynamic CT. In the control group, 19 (5%) of 393 patients also showed inhomogeneous enhancement in the early phase on dynamic CT. The frequency of inhomogeneous enhancement was significantly higher in the cholangitis group than in the control group (p < 0.001). Follow-up dynamic CT performed after treatment for acute cholangitis showed decreased inhomogeneous enhancement or no inhomogeneous enhancement in seven (78%) of nine patients in the cholangitis group. CONCLUSION: Inhomogeneous enhancement in the early phase on dynamic CT is frequently seen in patients with acute cholangitis; this finding usually disappears after treatment.

Acute Disease↗
PubMed2002

Groove pancreatic carcinomas: radiological and pathological findings.

The aim of this study was to clarify the characteristics of pancreatic head carcinomas mainly invading the groove between the duodenum and the pancreatic head. Nine patients with pathologically proven pancreatic head carcinomas underwent thin-slice dynamic CT, MR imaging, duodenal endoscopy, and angiography (seven patients). Plate-like masses within the groove region were seen in all cases, which showed hypointensity on T1-weighted images and slight hyperintensity on T2-weighted MR images. The masses appeared hypovascular in the early phase and delayed enhancement in the late phase of dynamic CT and MR imaging. On MR cholangiopancreatography, stenosis of intrapancreatic common bile duct was seen in all patients, whereas stenosis of the main pancreatic duct was seen in only three cases. Endoscopy revealed luminal narrowing of the duodenum in all patients, and duodenal mucosal biopsy demonstrated adenocarcinoma in seven patients. Abdominal arteriography showed serrated encasement of peripancreatic arteries in seven patients who received angiographic examinations. The CT and MR imaging findings of groove pancreatic carcinomas resemble those of groove pancreatitis. Differential diagnosis may be achieved by the pathological diagnosis of a biopsy specimen of the duodenal mucosa and arterial encasement on arteriography.

Adenocarcinoma↗
PubMed2002

Sphingosine-1-phosphate, a platelet-derived lysophospholipid mediator, negatively regulates cellular Rac activity and cell migration in vascular smooth muscle cells.

Previous studies demonstrated that sphingosine-1-phosphate (S1P) induced migration of human umbilical vein endothelial cells (HUVECs) whereas it inhibited that of vascular smooth muscle cells (SMCs). This study explored the molecular mechanisms underlying the contrasting S1P actions on vascular cell motility. In rat and human aortic SMCs, the chemoattractant platelet-derived growth factor B-chain (PDGF) induced rapid 5- to 6-fold increases in the cellular amount of GTP-bound, active form of Rac. S1P did not affect PDGF-stimulated tyrosine phosphorylation of PDGF-beta receptor, but strongly inhibited PDGF-induced Rac activation, with a dose-response relationship similar to that for inhibition of PDGF-elicited chemotaxis. Dihydrosphingosine-1-phosphate, which is a weaker agonist for the S1P receptors, but not an inactive ligand sphingosine, also inhibited PDGF-stimulated chemotaxis and Rac activation although to lesser extents compared with S1P, suggesting that negative regulation by S1P of both chemotaxis and Rac was a receptor-mediated process. In contrast, S1P by itself stimulated Rac activity in HUVECs. Among the five S1P receptor isoforms, SMCs prominently expressed Edg-5 mRNA, whereas HUVECs expressed abundant Edg-1 mRNA but lacked detectable expression of Edg-5 mRNA. Adenovirus-mediated expression of a dominant-negative form of either Rac or Cdc42, but not RhoA, markedly attenuated chemotaxis of SMCs and HUVECs toward PDGF and S1P, respectively. Overexpression of Edg-1 in SMCs and Edg-5 in HUVECs reduced S1P-induced inhibition and stimulation, respectively, of Rac activity and migration. These results together indicate that Edg isoform-specific, negative or positive regulation of cellular Rac activity is critically involved in S1P-mediated bimodal regulation of cell motility in SMCs and HUVECs.

Animals↗
PubMed2002

Tiny staining spots in liver cirrhosis associated with HCV infection observed by computed tomographic hepatic arteriography: follow-up study.

BACKGROUND: It is important to distinguish small lesions with increased arterial perfusion observed by computed tomographic arteriography (CT-A) from hepatocellular carcinoma (HCC). However, the clinical characteristics and prognosis of such lesions have not been clarified. METHODS: We retrospectively examined 200 patients with cirrhosis related to hepatitis C virus (HCV) infection who had undergone both CT-A and CT arterioportography between 1995 and 1998, and found 80 tiny staining spots (TSS)s, with a diameter of 5-10 mm, by CT-A (35 patients). The mean TSS observation period was 29.0 months. If the major axis was larger than 10 mm and showed a 1.5-fold or more increase, the lesion was regarded as tumor growth (TG). The TSS lesions were divided into two groups according to whether the patient had or did not have HCC. The prognosis of TSS was classified into three groups; HCC-suspected group, nontumor group, and unclassified group, in which TG was negative although transcatheter arterial embolization (TAE) had been performed. RESULTS: Of the 40 TSSs in 14 patients without HCC, 2 (5%) were suspected as HCC. Of the 40 TSSs in 21 patients with HCC, 13 (32.5%) were suspected as HCC. There were no significant differences in the size, position, and morphology of TSSs among the three prognostic groups. Of the 7 TSSs with a high signal intensity on T2-weighted magnetic resonance (MR) images, 5 were in the HCC-suspected group. CONCLUSIONS: We recommend early treatment of TSSs accompanying HCC or showing features of malignancy at the imaging workup.

Carcinoma, Hepatocellular↗
PubMed2002

Progression to hypervascular hepatocellular carcinoma: correlation with intranodular blood supply evaluated with CT during intraarterial injection of contrast material.

PURPOSE: To analyze the correlation between intranodular blood supply of borderline lesions (ie, dysplastic nodules or hypovascular well-differentiated hepatocellular carcinoma [HCC] nodules) and their progression to hypervascular classic HCC in cirrhotic livers. MATERIALS AND METHODS: One hundred seventy-six borderline lesions seen at computed tomography (CT) during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) were evaluated in 49 patients with cirrhosis who underwent repeated CTAP and/or CTHA but no therapy. On the basis of CTAP findings, nodules were categorized as group A (showing almost the same portal venous supply as the surrounding liver), group B (showing decreased portal venous supply) or group C (showing partially absent portal venous supply); on the basis of CTHA findings, nodules were categorized as group I (showing almost the same arterial supply as the liver), group II (showing decreased arterial supply), or group III (showing partially increased arterial supply). RESULTS: Progression to classic HCC was observed in 29.4% of group A nodules, 53.9% of group B nodules, and 87.9% of group C nodules within 1,000 days; in 58.6% of group I nodules, 12.9% of group II nodules, and 92.2% of group III nodules within 730 days; and in 0% of nodules in group A and I, 28% of nodules in group B and/or II, and 88.7% of nodules in group C and/or III within 730 days. CONCLUSION: Evaluation of intranodular blood supply was valuable in predicting the prognosis in borderline lesions, except when only arterial blood supply was evaluated.

Adult↗
PubMedDate not supplied

MR imaging of hepatocellular carcinomas with biliary tumor thrombi.

We retrospectively evaluate the MR imaging findings of hepatocellular carcinomas (HCC) with biliary tumor thrombi. MR imaging was performed on six patients presenting with obstructive jaundice and/or biliary hemorrhage. T1-weighted images, T2-weighted images, MR cholangiopancreatography (MRCP), and dynamic MR images were obtained. Duodenal endoscopy was performed on all cases and hepatic resection on two cases. HCCs were 1.8-10 cm in diameter (mean 5.8 cm). Biliary tumor thrombi were detected in all patients on MR imaging. Tumor thrombi showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and contrast enhancement on the early phase of dynamic MR images. MRCP showed intrahepatic bile duct dilatation in all cases. Biliary hemorrhage was clearly depicted by MR images in five cases and showed hyperintensity on T1-weighted images and hyperintensity or hypointensity on T2-weighted images. Biliary hemorrhage was confirmed by endoscopy in two cases. Portal vein thrombi were also associated in five of six patients. Pathologically, tumor thrombi of HCCs were demonstrated in two patients who underwent hepatic resection. In conclusion, MR imaging is useful for the diagnosis of biliary tumor thrombi from HCC and for evaluating the extension of thrombi and biliary hemorrhage.

Aged↗
PubMedDate not supplied

Abdominal aortic aneurysm with a dilated common iliac artery: treatment using a handmade bifurcated stent-graft with a wide iliac limb end.

The purpose of this study was to evaluate the usefulness of a bifurcated stent-graft with a wide iliac limb end (WILE) in the treatment of abdominal aortic aneurysm (AAA) with a dilated common iliac artery (CIA) to avoid occlusion of the internal iliac artery (IIA). The WILE, covered with an expanded polytetrafluoroethylene graft which was constructed of large diameter stents according to the individual CIA diameter, was connected to a two-piece bifurcated stent-graft covering a polyester graft. The WILE was placed in eight dilated CIAs of six patients. All but one WILE fitted the dilated CIA well. One did not fit, and coil embolization of the leak was needed. All eight IIA derived from the dilated CIA avoided occlusion. Perigraft leak due to other causes was identified in another two patients. Limb kinking was observed in two patients. Our stent is useful in the treatment of AAA with dilated CIA to avoid occlusion of the IIA, and may extend the indication of endoluminal repair of AAA.

Aged↗
PubMedDate not supplied

CO2 demonstration of multiple extravasations into a subcapsular hematoma of the liver.

In a case of esophageal cancer with liver metastases, rupture of a liver metastasis resulted in subcapsular hematoma of the liver. Digital subtraction angiography with carbon dioxide showed multiple extravasations at the surface of the liver suggesting multiple ruptures of the penetrating hepatic capsular arteries. It was suggested that these findings are not rare in cases of subcapsular hematoma; however, they have received little attention.

Angiography, Digital Subtraction↗
PubMedDate not supplied

Endovascular stent-grafting for infected iliac artery pseudoaneurysms.

We report two cases of acutely infected pseudoaneurysms of the iliac arteries, successfully treated with endovascular stent-grafting. Two patients underwent stent-graft treatment for erosive rupture of the iliac artery caused by surrounding infection. The first case is that of a 61-year-old man who had undergone Miles' operation for an advanced rectal cancer. Postoperatively, he developed intrapelvic abscess formation, from which methicillin-resistant Staphylococcus aureus was cultured, followed by rupture of the right external iliac artery. The second case is that of a 60-year-old man who had a pseudoaneurysm of the left common iliac artery, which was contiguous with a left psoas muscle abscess, from which Streptococcus agalactiae was cultured. Both patients were successfully treated with only a stent-graft and antibiotic therapy, and remained symptom-free 12 months and 10 months later. Although endovascular stent-grafting should not be considered standard therapy for infected aneurysms, our cases suggest that it can result in repair of infected aneurysms even in the uncontrolled active stage.

Aneurysm, False↗
PubMedDate not supplied

Occluded Brescia-cimino hemodialysis fistulas: endovascular treatment with both brachial arterial and venous access using the pull-through technique.

We retrospectively evaluated the usefulness of both arterial and venous access with the pull-through technique in endovascular treatment of totally occluded Brescia-Cimino fistulas. We treated 26 patients (17 men, 9 women; age range 43-82 years, mean age 66 years) with occluded Brescia-Cimino fistulas. First, the occluded segment was traversed from the antegrade brachial arterial access using a microcatheter-guidewire system. Second, the vein was retrogradely punctured after confirmation of all diseased segments, and a 0.014- or 0.016-inch guidewire was pulled through the venous access when the occluded segment was long. All interventions including thrombolysis, thromboaspiration, angioplasty, and stent placement were performed via the venous access. The occlusion was successfully crossed via the brachial arterial access in 23 patients (88%). In 2 patients it was done from the venous approach. In the remaining patient it was not possible to traverse the occluded segment. The pull-through technique was successful in all 19 attempts. Clinical success was achieved in 96%, the primary patency rates at 6, 12, and 18 months were 83%, 78%, and 69%, the primary assisted patency rates were 92%, 92%, and 72%, and the secondary patency rates were 92%, 92%, and 92%, respectively. Minor complications in 5 patients included venous perforation in 2 (8%), venous rupture in 1 (4%), and regional hematoma in 2 (8%). Our study suggests that endovascular treatments with both arterial and venous access using the pull-through technique are highly effective in restoring function in totally occluded Brescia-Cimino fistulas.

Adult↗
PubMedDate not supplied

Extrahepatic blood supply to hepatocellular carcinoma: angiographic demonstration and transcatheter arterial chemoembolization.

PURPOSE: To evaluate the incidence of each extrahepatic collateral pathway to hepatocellular carcinoma (HCC) and to assess technical success rates and complications of transcatheter arterial chemoembolization (TACE) through each collateral. METHODS: We retrospective evaluated extrahepatic collateral pathways to HCC on angiography in 386 procedures on 181 consecutive patients. One hundred and seventy patients had previously undergone TACE. TACE through extrahepatic collaterals using iodized oil and gelatin sponge particles was performed when a catheter was advanced into the tumor-feeding branch to avoid nontarget embolization. RESULTS: A single collateral was revealed in 275 TACE procedures, two were revealed in 74, and three or more were revealed in 34. Incidences of collateral source to HCC were 83% from the right inferior phrenic artery (IPA), 24% from the cystic artery, 13% from the omental artery, 12% from the right renal capsular artery (RCA) and left IPA, 8% from the right internal mammary artery (IMA) and right intercostal artery (ICA), and 7% from the right inferior adrenal artery (IAA). Technical success rates of TACE were 53% in the right ICA, 70% in the cystic artery, 74% in the omental artery, 93% in the left IPA, 96% in the right IPA, and 100% in the right RCA, right IMA, and right IAA. Complications included skin necrosis after TACE through the right IMA (n = 1), cholecystitis after TACE through the cystic artery (n = 1), and ulcer formation after TACE through the right gastric artery (n = 1), in addition to pleural effusion and basal atelectasis after TACE through the IPA and IMA. CONCLUSION: Our study suggests that TACE through extrahepatic collaterals is possible with high success rates, and is also relatively safe.

Adult↗
PubMedDate not supplied

Usefulness of grasping a guiding catheter with a loop-snare wire for stent placement into the vertebrobasilar artery.

In cases in which the subclavian artery is severely tortuous or branches with an extremely angulated origin, stent placement in the vertebrobasilar artery on the approach from the femoral artery is often technically difficult. We report two cases in which a stent placement procedure for the vertebrobasilar artery was successfully performed by grasping a guiding catheter with a loop-snare wire. This technique is useful for tortuous arteries or arteries branching with an extremely angulated origin.

Aged↗
PubMedDate not supplied

Feeding artery of laryngeal and hypopharyngeal cancers: role of the superior thyroid artery in superselective intraarterial chemotherapy.

The purpose of this study was to elucidate the role of the superior thyroid artery in intra-arterial infusion chemotherapy for laryngeal and hypopharyngeal cancers. Thirty-nine patients with laryngeal cancer and 29 patients with hypopharyngeal cancer underwent intra-arterial infusion chemotherapy. We performed a retrospective analysis of the feeding arteries confirmed by computed tomography during selective arteriography and compared the results with the extent of the tumors. In 14 of 39 laryngeal and 15 of 29 hypopharyngeal cancers, the tumor did not cross the midline (group 1). In the remaining 25 and 14 cancers, respectively, the tumor crossed the midline or located in the center (group 2). For 13 of 14 laryngeal and 7 of 15 hypopharyngeal cancers in group 1 and for 6 of 25 laryngeal cancers in group 2, the entire tumor was contrast enhanced by the ipsilateral superior thyroid and/or superior laryngeal artery. For 12 of 25 laryngeal and 1 of 14 hypopharyngeal cancers in group 2, the entire tumor was contrast enhanced by the bilateral superior thyroid artery. For the other patients, infusion via the other arterial branches such as the inferior thyroid and the lingual arteries were needed to achieve contrast enhancement of the entire tumor. Superselective intra-arterial chemotherapy for laryngeal cancer from the superior thyroid artery is appropriate, whereas that for hypopharyngeal cancer is less sufficient. To accomplish contrast enhancement of the entire tumor, additional intra-arterial infusion from other arteries such as the inferior thyroid artery is often necessary.

Aged↗
PubMedDate not supplied

Bronchial artery aneurysm embolization with NBCA.

We present a case of asymptomatic bronchial artery aneurysm that formed a fistula with part of the pulmonary artery (there was no definite fistula with the pulmonary vein). We were able to catheterize the feeding vessel but could not reach the aneurysm. We therefore injected a mixture of N-butyl-2-cyanoacrylate (NBCA; Histoacryl, B. Braun, Melsungen, Germany) and iodized oil (Lipiodol; Guerbet, Aulnay-sous-Bois, France) from the feeding vessel. The fistula, aneurysm, and feeding vessel were almost totally occluded. After embolization, the patient coughed a little; there were no other definite side effects or complications. One and 3 months later, on chest CT, the aneurysm was almost completely occupied with hyperattenuating NBCA-Lipiodol embolization. NBCA is a liquid embolization material whose time to coagulation after injection can be controlled by diluting it with Lipiodol. It is therefore possible to embolize an aneurysm, feeding vessels, and efferent vessels (in our case, it was a fistula) by using an NBCA-Lipiodol mixture of an appropriate concentration, regardless of whether the catheter can reach the aneurysm or not.

Adult↗